Treatment for nightmares
It has been suggested that people who suffer from nightmares could benefit from the ability to be aware they are indeed dreaming. A pilot study was performed in 2006 that showed that lucid dreaming treatment was successful in reducing nightmare frequency. This treatment consisted of exposure to the idea, mastery of the technique, and lucidity exercises. It was not clear what aspects of the treatment were responsible for the success of overcoming nightmares, though the treatment as a whole was successful.
Australian psychologist Milan Colic has explored the application of principles from narrative therapy with clients' lucid dreams, to reduce the impact not only of nightmares during sleep, but also depression, self-mutilation, and other problems in waking life. Colic found that clients' preferred direction for their lives, as identified during therapeutic conversations, could lessen the distressing content of dreams, while understandings about life—and even characters—from lucid dreams could be invoked in "real" life with marked therapeutic benefits.
source: Wikipedia